71 Dart get 408/ Trick Flow Heads....

I’m pretty surprised at how thin the bottom of that lifter is.

Look how cupped this one is...... still no big hole in it:

0A8C6BEE-D003-411E-A686-55270CA35B3C.jpeg

I’d be tempted to take a cutoff wheel to one of the remaining “good ones” to see how thick it is to start with.